A motor driver can have a controller that generates a pulse-width modulated signal used to produce drive signals for driver switches for different phases of a motor. The pulse-width modulated signal can specify the drive parameters for the motor. The pulse-width modulated signal can be generated based in-part on an internal oscillator of a component. This arrangement is suitable where there is one motor in control.
In applications employing redundancy of motors or motor windings where multiple pulse-width modulated signals are used to specify the drive parameters for the redundant windings or motors, if the pulse-width modulated signals are not synchronized torque ripple, vibration, noise, harshness, or the like can result. In some cases, the internal oscillators of multiple drive components, on which a pulse-width modulated signal is based, can have manufacturing tolerances that can cause two different oscillators to have different frequencies.
A way of synchronizing the internal oscillators is needed so that the corresponding pulse-width modulated signals are also synchronized in order to synchronize control of redundant motor systems.